CENTCOM's Twitter and YouTube accounts are back up and running after Islamic State sympathizers hacked the sites yesterday. The Defense Department says the attack lasted for about 30 minutes. The sites posted threatening messages about American troops and showed pro-Islamic State images. Retired Navy Rear Adm. Jamie Barnett is a partner for the cybersecurity practice at Venable. On In Depth with Francis Rose, he explained what the cybervandalism means for CENTCOM and national security.

Adm. Mike Rogers, commander of the U.S. Cyber Command and director of the National Security Agency, told the House Intelligence Committee that China, and perhaps other countries, will be able to shut down and damage critical infrastructure in the United States by 2025. Richard Stiennon is executive editor of the Security Current blog and founder of IT Harvest. On In Depth with Francis Rose, he said only one part of Rogers' comment seems off the mark.

U.S. Cyber Command is reviewing the results of its biggest exercise of the year. CYBERFLAG is designed to test out the military forces' ability to keep fighting when an adversary is attacking their networks, and to link up cyber forces with the more traditional air, sea, land and space domains. Rear Adm. Kevin Lunday is Cyber Command's director for exercises and training. On In Depth with Francis Rose, he talked about the exercise -- and the three types of teams involved in it -- with Federal News Radio DoD Reporter Jared Serbu.

The leader of the Army's new Cyber Center of Excellence says his job is not merely to build the cyber workforce, but to integrate that up-and-coming capability with the Army's existing signals and intelligence disciplines.

The Army has activated a new brigade, a cyber brigade, its first ever. The brigade is part of the Army's Cyber Command. The brigade will be divided into teams consisting of both soldiers and civilians. Their primary mission will be to conduct defensive cyberspace operations. Army Col. Donald Bray is commander of the Cyber Protection Brigade in Fort Gordon, Georgia. He joined Tom Temin on the Federal Drive to discuss the brigade's structure and mission.

The first change of command at U.S. Cyber Command is complete. General Keith Alexander made way for Admiral Mike Rogers recently. But new revelations from Edward Snowden are a reminder that the first four years of the combination of CYBERCOM and the National Security Agency aren't without controversy. William Lynn was Deputy Secretary of Defense when the Defense Department stood up Cyber Command. He wrote about the strategy behind it in Foreign Policy at the time. He is now Chief Executive Officer of Finmeccanica North America and DRS Technologies. He explained on In Depth with Francis Rose the chain of events that caused DoD leadership to stand up Cyber Command.

Gen. Keith Alexander, who will soon retire as the first commander of U.S. Cyber Command, said his organization has matured to the point that it should join the club of unified commands that report directly to the President.

The Army still doesn't know whether its new and growing force of soldiers dedicated to cyber missions is large enough for the task. But it's certain it doesn't have the legal authorities it needs to attract and retain the talent it wants.

Command Sgt. Maj. Rodney Harris, the senior enlisted advisor at Army Cyber Command, said the Army is doing a good job at finding the right soldiers with the necessary skill sets to become cyber warriors.

Gen. Keith Alexander, head of the U.S. Cyber Command and the National Security Agency, said the greatest impact of the ongoing government shutdown on cybersecurity is on the morale of the cyber workforce.